According to The Mayo Clinic (one of the most respected medical centers in the world) http://www.mayoclinic.com/health/heart-disease/DS01120

Heart disease is a broad term used to describe a range of diseases that affect your heart, and in some cases, your blood vessels. The various diseases that fall under the umbrella of heart disease include diseases of your blood vessels, such as coronary artery disease; heart rhythm problems (arrhythmias); and heart defects you're born with (congenital heart defects).

The term "heart disease" is often used interchangeably with "cardiovascular disease" — a term that generally refers to conditions that involve narrowed or blocked blood vessels that can lead to a heart attack, chest pain (angina) or stroke. Other heart conditions, such as infections and conditions that affect your heart's muscle, valves or beating rhythm also are considered forms of heart disease.

Heart disease is the No. 1 worldwide killer of men and women, including in the United States. For example, heart disease is responsible for 40 percent of all the deaths in the United States, more than all forms of cancer combined. Many forms of heart disease can be prevented or treated with healthy lifestyle choices and diet and exercise.

Heart disease symptoms vary, depending on what type of heart disease you have.
Heart disease or cardiovascular disease is caused by narrowed, blocked or stiffened blood vessels that make it so your heart, brain or other parts of your body don't receive enough blood. Cardiovascular disease symptoms can include: 

• Chest pain (angina) 
• Shortness of breath 
• Pain, numbness, weakness or coldness in your legs or arms, if the blood vessels in those parts of your body are narrowed

You might not be diagnosed with cardiovascular disease until your condition worsens to the point that you have a heart attack, chest pain (angina), stroke, heart failure or sudden cardiac death. It's important to watch for cardiovascular symptoms and discuss any concerns with your doctor. Cardiovascular disease can sometimes be found early with regular visits to your doctor.

When to see a doctor
Seek emergency medical care if you have these heart disease symptoms:

• Chest pain 
• Shortness of breath
• Fainting

Heart disease is easier to treat when it's detected early, so talk to your doctor about any concerns you have about your heart health. If you don't have heart disease, but are concerned about developing heart disease, talk to your doctor about steps you can take to reduce your heart disease risk. This is especially true if you have a family history of heart disease.

If you think you may have heart disease based on new signs or symptoms you've been having, make an appointment to see your doctor. 

Heart disease symptoms caused by abnormal heartbeats (heart arrhythmias). A heart arrhythmia is an abnormal heartbeat. Your heart may beat too quickly, too slowly, or irregularly if you have an arrhythmia. Heart arrhythmia symptoms can include: 

• A fluttering in your chest 
• A racing heartbeat (tachycardia) 
• A slow heartbeat (bradycardia)
• Chest pain 
• Shortness of breath
• Lightheadedness 
• Dizziness
• Fainting (syncope) or near fainting

Heart disease symptoms caused by thick heart muscle (cardiomyopathy). Cardiomyopathy is the thickening and stiffening of heart muscle. In early stages of cardiomyopathy, you may have no symptoms. As the condition worsens, cardiomyopathy symptoms include: 

• Breathlessness with exertion or even at rest 
• Swelling of the legs, ankles and feet 
• Bloating (distention) of the abdomen with fluid 
• Fatigue 
• Irregular heartbeats that feel rapid, pounding or fluttering
• Dizziness, lightheadedness and fainting

Heart disease symptoms caused by heart defects. Serious congenital heart defects — a defect you're born with — usually become evident during the first few hours, days, weeks and months of life. Heart defect symptoms could include: 

• Pale gray or blue skin color (cyanosis) 
• Swelling in the legs, abdomen or areas around the eyes 
• Shortness of breath during feedings, leading to poor weight gain

Less-serious congenital heart defects are often not diagnosed until later in childhood or even adulthood. Signs and symptoms of congenital heart defects that usually aren't immediately life-threatening include: 

• Easily becoming short of breath during exercise or activity 
• Easily tiring during exercise or activity 
• Built-up fluid in the heart or lungs 
• Swelling in the hands, ankles or feet

• Fever
• Shortness of breath
• Weakness or fatigue
• Swelling in your legs or abdomen
• Changes in your heart rhythm
• Dry or persistent cough
• Skin rashes or unusual spots

• Fatigue 
• Shortness of breath
• Irregular heartbeat or heart murmur
• Swollen feet or ankles
• Chest pain
• Fainting (syncope)